81439695 has 16 divisors (see below), whose sum is σ = 144781920. Its totient is φ = 43434432.

The previous prime is 81439679. The next prime is 81439703. The reversal of 81439695 is 59693418.

It is a happy number.

It is not a de Polignac number, because 81439695 - 2⁴ = 81439679 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 81439695.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 301494 + ... + 301763.

It is an arithmetic number, because the mean of its divisors is an integer number (9048870).

Almost surely, 2^81439695 is an apocalyptic number.

81439695 is a deficient number, since it is larger than the sum of its proper divisors (63342225).

81439695 is a wasteful number, since it uses less digits than its factorization.

81439695 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 603271 (or 603265 counting only the distinct ones).

The product of its digits is 233280, while the sum is 45.

The square root of 81439695 is about 9024.3944395178. The cubic root of 81439695 is about 433.4563598746.

The spelling of 81439695 in words is "eighty-one million, four hundred thirty-nine thousand, six hundred ninety-five".